1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Generic infrastructure for lifetime debugging of objects. |
4 | * |
5 | * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de> |
6 | */ |
7 | |
8 | #define pr_fmt(fmt) "ODEBUG: " fmt |
9 | |
10 | #include <linux/debugobjects.h> |
11 | #include <linux/interrupt.h> |
12 | #include <linux/sched.h> |
13 | #include <linux/sched/task_stack.h> |
14 | #include <linux/seq_file.h> |
15 | #include <linux/debugfs.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/hash.h> |
18 | #include <linux/kmemleak.h> |
19 | #include <linux/cpu.h> |
20 | |
21 | #define ODEBUG_HASH_BITS 14 |
22 | #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) |
23 | |
24 | #define ODEBUG_POOL_SIZE 1024 |
25 | #define ODEBUG_POOL_MIN_LEVEL 256 |
26 | #define ODEBUG_POOL_PERCPU_SIZE 64 |
27 | #define ODEBUG_BATCH_SIZE 16 |
28 | |
29 | #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT |
30 | #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT) |
31 | #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1)) |
32 | |
33 | /* |
34 | * We limit the freeing of debug objects via workqueue at a maximum |
35 | * frequency of 10Hz and about 1024 objects for each freeing operation. |
36 | * So it is freeing at most 10k debug objects per second. |
37 | */ |
38 | #define ODEBUG_FREE_WORK_MAX 1024 |
39 | #define ODEBUG_FREE_WORK_DELAY DIV_ROUND_UP(HZ, 10) |
40 | |
41 | struct debug_bucket { |
42 | struct hlist_head list; |
43 | raw_spinlock_t lock; |
44 | }; |
45 | |
46 | /* |
47 | * Debug object percpu free list |
48 | * Access is protected by disabling irq |
49 | */ |
50 | struct debug_percpu_free { |
51 | struct hlist_head free_objs; |
52 | int obj_free; |
53 | }; |
54 | |
55 | static DEFINE_PER_CPU(struct debug_percpu_free, percpu_obj_pool); |
56 | |
57 | static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE]; |
58 | |
59 | static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata; |
60 | |
61 | static DEFINE_RAW_SPINLOCK(pool_lock); |
62 | |
63 | static HLIST_HEAD(obj_pool); |
64 | static HLIST_HEAD(obj_to_free); |
65 | |
66 | /* |
67 | * Because of the presence of percpu free pools, obj_pool_free will |
68 | * under-count those in the percpu free pools. Similarly, obj_pool_used |
69 | * will over-count those in the percpu free pools. Adjustments will be |
70 | * made at debug_stats_show(). Both obj_pool_min_free and obj_pool_max_used |
71 | * can be off. |
72 | */ |
73 | static int obj_pool_min_free = ODEBUG_POOL_SIZE; |
74 | static int obj_pool_free = ODEBUG_POOL_SIZE; |
75 | static int obj_pool_used; |
76 | static int obj_pool_max_used; |
77 | static bool obj_freeing; |
78 | /* The number of objs on the global free list */ |
79 | static int obj_nr_tofree; |
80 | |
81 | static int debug_objects_maxchain __read_mostly; |
82 | static int __maybe_unused debug_objects_maxchecked __read_mostly; |
83 | static int debug_objects_fixups __read_mostly; |
84 | static int debug_objects_warnings __read_mostly; |
85 | static int debug_objects_enabled __read_mostly |
86 | = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT; |
87 | static int debug_objects_pool_size __read_mostly |
88 | = ODEBUG_POOL_SIZE; |
89 | static int debug_objects_pool_min_level __read_mostly |
90 | = ODEBUG_POOL_MIN_LEVEL; |
91 | static const struct debug_obj_descr *descr_test __read_mostly; |
92 | static struct kmem_cache *obj_cache __ro_after_init; |
93 | |
94 | /* |
95 | * Track numbers of kmem_cache_alloc()/free() calls done. |
96 | */ |
97 | static int debug_objects_allocated; |
98 | static int debug_objects_freed; |
99 | |
100 | static void free_obj_work(struct work_struct *work); |
101 | static DECLARE_DELAYED_WORK(debug_obj_work, free_obj_work); |
102 | |
103 | static int __init enable_object_debug(char *str) |
104 | { |
105 | debug_objects_enabled = 1; |
106 | return 0; |
107 | } |
108 | |
109 | static int __init disable_object_debug(char *str) |
110 | { |
111 | debug_objects_enabled = 0; |
112 | return 0; |
113 | } |
114 | |
115 | early_param("debug_objects" , enable_object_debug); |
116 | early_param("no_debug_objects" , disable_object_debug); |
117 | |
118 | static const char *obj_states[ODEBUG_STATE_MAX] = { |
119 | [ODEBUG_STATE_NONE] = "none" , |
120 | [ODEBUG_STATE_INIT] = "initialized" , |
121 | [ODEBUG_STATE_INACTIVE] = "inactive" , |
122 | [ODEBUG_STATE_ACTIVE] = "active" , |
123 | [ODEBUG_STATE_DESTROYED] = "destroyed" , |
124 | [ODEBUG_STATE_NOTAVAILABLE] = "not available" , |
125 | }; |
126 | |
127 | static void fill_pool(void) |
128 | { |
129 | gfp_t gfp = __GFP_HIGH | __GFP_NOWARN; |
130 | struct debug_obj *obj; |
131 | unsigned long flags; |
132 | |
133 | if (likely(READ_ONCE(obj_pool_free) >= debug_objects_pool_min_level)) |
134 | return; |
135 | |
136 | /* |
137 | * Reuse objs from the global free list; they will be reinitialized |
138 | * when allocating. |
139 | * |
140 | * Both obj_nr_tofree and obj_pool_free are checked locklessly; the |
141 | * READ_ONCE()s pair with the WRITE_ONCE()s in pool_lock critical |
142 | * sections. |
143 | */ |
144 | while (READ_ONCE(obj_nr_tofree) && (READ_ONCE(obj_pool_free) < obj_pool_min_free)) { |
145 | raw_spin_lock_irqsave(&pool_lock, flags); |
146 | /* |
147 | * Recheck with the lock held as the worker thread might have |
148 | * won the race and freed the global free list already. |
149 | */ |
150 | while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) { |
151 | obj = hlist_entry(obj_to_free.first, typeof(*obj), node); |
152 | hlist_del(n: &obj->node); |
153 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1); |
154 | hlist_add_head(n: &obj->node, h: &obj_pool); |
155 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
156 | } |
157 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
158 | } |
159 | |
160 | if (unlikely(!obj_cache)) |
161 | return; |
162 | |
163 | while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) { |
164 | struct debug_obj *new[ODEBUG_BATCH_SIZE]; |
165 | int cnt; |
166 | |
167 | for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) { |
168 | new[cnt] = kmem_cache_zalloc(k: obj_cache, flags: gfp); |
169 | if (!new[cnt]) |
170 | break; |
171 | } |
172 | if (!cnt) |
173 | return; |
174 | |
175 | raw_spin_lock_irqsave(&pool_lock, flags); |
176 | while (cnt) { |
177 | hlist_add_head(n: &new[--cnt]->node, h: &obj_pool); |
178 | debug_objects_allocated++; |
179 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
180 | } |
181 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
182 | } |
183 | } |
184 | |
185 | /* |
186 | * Lookup an object in the hash bucket. |
187 | */ |
188 | static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) |
189 | { |
190 | struct debug_obj *obj; |
191 | int cnt = 0; |
192 | |
193 | hlist_for_each_entry(obj, &b->list, node) { |
194 | cnt++; |
195 | if (obj->object == addr) |
196 | return obj; |
197 | } |
198 | if (cnt > debug_objects_maxchain) |
199 | debug_objects_maxchain = cnt; |
200 | |
201 | return NULL; |
202 | } |
203 | |
204 | /* |
205 | * Allocate a new object from the hlist |
206 | */ |
207 | static struct debug_obj *__alloc_object(struct hlist_head *list) |
208 | { |
209 | struct debug_obj *obj = NULL; |
210 | |
211 | if (list->first) { |
212 | obj = hlist_entry(list->first, typeof(*obj), node); |
213 | hlist_del(n: &obj->node); |
214 | } |
215 | |
216 | return obj; |
217 | } |
218 | |
219 | static struct debug_obj * |
220 | alloc_object(void *addr, struct debug_bucket *b, const struct debug_obj_descr *descr) |
221 | { |
222 | struct debug_percpu_free *percpu_pool = this_cpu_ptr(&percpu_obj_pool); |
223 | struct debug_obj *obj; |
224 | |
225 | if (likely(obj_cache)) { |
226 | obj = __alloc_object(list: &percpu_pool->free_objs); |
227 | if (obj) { |
228 | percpu_pool->obj_free--; |
229 | goto init_obj; |
230 | } |
231 | } |
232 | |
233 | raw_spin_lock(&pool_lock); |
234 | obj = __alloc_object(list: &obj_pool); |
235 | if (obj) { |
236 | obj_pool_used++; |
237 | WRITE_ONCE(obj_pool_free, obj_pool_free - 1); |
238 | |
239 | /* |
240 | * Looking ahead, allocate one batch of debug objects and |
241 | * put them into the percpu free pool. |
242 | */ |
243 | if (likely(obj_cache)) { |
244 | int i; |
245 | |
246 | for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { |
247 | struct debug_obj *obj2; |
248 | |
249 | obj2 = __alloc_object(list: &obj_pool); |
250 | if (!obj2) |
251 | break; |
252 | hlist_add_head(n: &obj2->node, |
253 | h: &percpu_pool->free_objs); |
254 | percpu_pool->obj_free++; |
255 | obj_pool_used++; |
256 | WRITE_ONCE(obj_pool_free, obj_pool_free - 1); |
257 | } |
258 | } |
259 | |
260 | if (obj_pool_used > obj_pool_max_used) |
261 | obj_pool_max_used = obj_pool_used; |
262 | |
263 | if (obj_pool_free < obj_pool_min_free) |
264 | obj_pool_min_free = obj_pool_free; |
265 | } |
266 | raw_spin_unlock(&pool_lock); |
267 | |
268 | init_obj: |
269 | if (obj) { |
270 | obj->object = addr; |
271 | obj->descr = descr; |
272 | obj->state = ODEBUG_STATE_NONE; |
273 | obj->astate = 0; |
274 | hlist_add_head(n: &obj->node, h: &b->list); |
275 | } |
276 | return obj; |
277 | } |
278 | |
279 | /* |
280 | * workqueue function to free objects. |
281 | * |
282 | * To reduce contention on the global pool_lock, the actual freeing of |
283 | * debug objects will be delayed if the pool_lock is busy. |
284 | */ |
285 | static void free_obj_work(struct work_struct *work) |
286 | { |
287 | struct hlist_node *tmp; |
288 | struct debug_obj *obj; |
289 | unsigned long flags; |
290 | HLIST_HEAD(tofree); |
291 | |
292 | WRITE_ONCE(obj_freeing, false); |
293 | if (!raw_spin_trylock_irqsave(&pool_lock, flags)) |
294 | return; |
295 | |
296 | if (obj_pool_free >= debug_objects_pool_size) |
297 | goto free_objs; |
298 | |
299 | /* |
300 | * The objs on the pool list might be allocated before the work is |
301 | * run, so recheck if pool list it full or not, if not fill pool |
302 | * list from the global free list. As it is likely that a workload |
303 | * may be gearing up to use more and more objects, don't free any |
304 | * of them until the next round. |
305 | */ |
306 | while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) { |
307 | obj = hlist_entry(obj_to_free.first, typeof(*obj), node); |
308 | hlist_del(n: &obj->node); |
309 | hlist_add_head(n: &obj->node, h: &obj_pool); |
310 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
311 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1); |
312 | } |
313 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
314 | return; |
315 | |
316 | free_objs: |
317 | /* |
318 | * Pool list is already full and there are still objs on the free |
319 | * list. Move remaining free objs to a temporary list to free the |
320 | * memory outside the pool_lock held region. |
321 | */ |
322 | if (obj_nr_tofree) { |
323 | hlist_move_list(old: &obj_to_free, new: &tofree); |
324 | debug_objects_freed += obj_nr_tofree; |
325 | WRITE_ONCE(obj_nr_tofree, 0); |
326 | } |
327 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
328 | |
329 | hlist_for_each_entry_safe(obj, tmp, &tofree, node) { |
330 | hlist_del(n: &obj->node); |
331 | kmem_cache_free(s: obj_cache, objp: obj); |
332 | } |
333 | } |
334 | |
335 | static void __free_object(struct debug_obj *obj) |
336 | { |
337 | struct debug_obj *objs[ODEBUG_BATCH_SIZE]; |
338 | struct debug_percpu_free *percpu_pool; |
339 | int lookahead_count = 0; |
340 | unsigned long flags; |
341 | bool work; |
342 | |
343 | local_irq_save(flags); |
344 | if (!obj_cache) |
345 | goto free_to_obj_pool; |
346 | |
347 | /* |
348 | * Try to free it into the percpu pool first. |
349 | */ |
350 | percpu_pool = this_cpu_ptr(&percpu_obj_pool); |
351 | if (percpu_pool->obj_free < ODEBUG_POOL_PERCPU_SIZE) { |
352 | hlist_add_head(n: &obj->node, h: &percpu_pool->free_objs); |
353 | percpu_pool->obj_free++; |
354 | local_irq_restore(flags); |
355 | return; |
356 | } |
357 | |
358 | /* |
359 | * As the percpu pool is full, look ahead and pull out a batch |
360 | * of objects from the percpu pool and free them as well. |
361 | */ |
362 | for (; lookahead_count < ODEBUG_BATCH_SIZE; lookahead_count++) { |
363 | objs[lookahead_count] = __alloc_object(list: &percpu_pool->free_objs); |
364 | if (!objs[lookahead_count]) |
365 | break; |
366 | percpu_pool->obj_free--; |
367 | } |
368 | |
369 | free_to_obj_pool: |
370 | raw_spin_lock(&pool_lock); |
371 | work = (obj_pool_free > debug_objects_pool_size) && obj_cache && |
372 | (obj_nr_tofree < ODEBUG_FREE_WORK_MAX); |
373 | obj_pool_used--; |
374 | |
375 | if (work) { |
376 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1); |
377 | hlist_add_head(n: &obj->node, h: &obj_to_free); |
378 | if (lookahead_count) { |
379 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + lookahead_count); |
380 | obj_pool_used -= lookahead_count; |
381 | while (lookahead_count) { |
382 | hlist_add_head(n: &objs[--lookahead_count]->node, |
383 | h: &obj_to_free); |
384 | } |
385 | } |
386 | |
387 | if ((obj_pool_free > debug_objects_pool_size) && |
388 | (obj_nr_tofree < ODEBUG_FREE_WORK_MAX)) { |
389 | int i; |
390 | |
391 | /* |
392 | * Free one more batch of objects from obj_pool. |
393 | */ |
394 | for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { |
395 | obj = __alloc_object(list: &obj_pool); |
396 | hlist_add_head(n: &obj->node, h: &obj_to_free); |
397 | WRITE_ONCE(obj_pool_free, obj_pool_free - 1); |
398 | WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1); |
399 | } |
400 | } |
401 | } else { |
402 | WRITE_ONCE(obj_pool_free, obj_pool_free + 1); |
403 | hlist_add_head(n: &obj->node, h: &obj_pool); |
404 | if (lookahead_count) { |
405 | WRITE_ONCE(obj_pool_free, obj_pool_free + lookahead_count); |
406 | obj_pool_used -= lookahead_count; |
407 | while (lookahead_count) { |
408 | hlist_add_head(n: &objs[--lookahead_count]->node, |
409 | h: &obj_pool); |
410 | } |
411 | } |
412 | } |
413 | raw_spin_unlock(&pool_lock); |
414 | local_irq_restore(flags); |
415 | } |
416 | |
417 | /* |
418 | * Put the object back into the pool and schedule work to free objects |
419 | * if necessary. |
420 | */ |
421 | static void free_object(struct debug_obj *obj) |
422 | { |
423 | __free_object(obj); |
424 | if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) { |
425 | WRITE_ONCE(obj_freeing, true); |
426 | schedule_delayed_work(dwork: &debug_obj_work, ODEBUG_FREE_WORK_DELAY); |
427 | } |
428 | } |
429 | |
430 | #ifdef CONFIG_HOTPLUG_CPU |
431 | static int object_cpu_offline(unsigned int cpu) |
432 | { |
433 | struct debug_percpu_free *percpu_pool; |
434 | struct hlist_node *tmp; |
435 | struct debug_obj *obj; |
436 | unsigned long flags; |
437 | |
438 | /* Remote access is safe as the CPU is dead already */ |
439 | percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu); |
440 | hlist_for_each_entry_safe(obj, tmp, &percpu_pool->free_objs, node) { |
441 | hlist_del(n: &obj->node); |
442 | kmem_cache_free(s: obj_cache, objp: obj); |
443 | } |
444 | |
445 | raw_spin_lock_irqsave(&pool_lock, flags); |
446 | obj_pool_used -= percpu_pool->obj_free; |
447 | debug_objects_freed += percpu_pool->obj_free; |
448 | raw_spin_unlock_irqrestore(&pool_lock, flags); |
449 | |
450 | percpu_pool->obj_free = 0; |
451 | |
452 | return 0; |
453 | } |
454 | #endif |
455 | |
456 | /* |
457 | * We run out of memory. That means we probably have tons of objects |
458 | * allocated. |
459 | */ |
460 | static void debug_objects_oom(void) |
461 | { |
462 | struct debug_bucket *db = obj_hash; |
463 | struct hlist_node *tmp; |
464 | HLIST_HEAD(freelist); |
465 | struct debug_obj *obj; |
466 | unsigned long flags; |
467 | int i; |
468 | |
469 | pr_warn("Out of memory. ODEBUG disabled\n" ); |
470 | |
471 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
472 | raw_spin_lock_irqsave(&db->lock, flags); |
473 | hlist_move_list(old: &db->list, new: &freelist); |
474 | raw_spin_unlock_irqrestore(&db->lock, flags); |
475 | |
476 | /* Now free them */ |
477 | hlist_for_each_entry_safe(obj, tmp, &freelist, node) { |
478 | hlist_del(n: &obj->node); |
479 | free_object(obj); |
480 | } |
481 | } |
482 | } |
483 | |
484 | /* |
485 | * We use the pfn of the address for the hash. That way we can check |
486 | * for freed objects simply by checking the affected bucket. |
487 | */ |
488 | static struct debug_bucket *get_bucket(unsigned long addr) |
489 | { |
490 | unsigned long hash; |
491 | |
492 | hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS); |
493 | return &obj_hash[hash]; |
494 | } |
495 | |
496 | static void debug_print_object(struct debug_obj *obj, char *msg) |
497 | { |
498 | const struct debug_obj_descr *descr = obj->descr; |
499 | static int limit; |
500 | |
501 | /* |
502 | * Don't report if lookup_object_or_alloc() by the current thread |
503 | * failed because lookup_object_or_alloc()/debug_objects_oom() by a |
504 | * concurrent thread turned off debug_objects_enabled and cleared |
505 | * the hash buckets. |
506 | */ |
507 | if (!debug_objects_enabled) |
508 | return; |
509 | |
510 | if (limit < 5 && descr != descr_test) { |
511 | void *hint = descr->debug_hint ? |
512 | descr->debug_hint(obj->object) : NULL; |
513 | limit++; |
514 | WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " |
515 | "object: %p object type: %s hint: %pS\n" , |
516 | msg, obj_states[obj->state], obj->astate, |
517 | obj->object, descr->name, hint); |
518 | } |
519 | debug_objects_warnings++; |
520 | } |
521 | |
522 | /* |
523 | * Try to repair the damage, so we have a better chance to get useful |
524 | * debug output. |
525 | */ |
526 | static bool |
527 | debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state), |
528 | void * addr, enum debug_obj_state state) |
529 | { |
530 | if (fixup && fixup(addr, state)) { |
531 | debug_objects_fixups++; |
532 | return true; |
533 | } |
534 | return false; |
535 | } |
536 | |
537 | static void debug_object_is_on_stack(void *addr, int onstack) |
538 | { |
539 | int is_on_stack; |
540 | static int limit; |
541 | |
542 | if (limit > 4) |
543 | return; |
544 | |
545 | is_on_stack = object_is_on_stack(obj: addr); |
546 | if (is_on_stack == onstack) |
547 | return; |
548 | |
549 | limit++; |
550 | if (is_on_stack) |
551 | pr_warn("object %p is on stack %p, but NOT annotated.\n" , addr, |
552 | task_stack_page(current)); |
553 | else |
554 | pr_warn("object %p is NOT on stack %p, but annotated.\n" , addr, |
555 | task_stack_page(current)); |
556 | |
557 | WARN_ON(1); |
558 | } |
559 | |
560 | static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket *b, |
561 | const struct debug_obj_descr *descr, |
562 | bool onstack, bool alloc_ifstatic) |
563 | { |
564 | struct debug_obj *obj = lookup_object(addr, b); |
565 | enum debug_obj_state state = ODEBUG_STATE_NONE; |
566 | |
567 | if (likely(obj)) |
568 | return obj; |
569 | |
570 | /* |
571 | * debug_object_init() unconditionally allocates untracked |
572 | * objects. It does not matter whether it is a static object or |
573 | * not. |
574 | * |
575 | * debug_object_assert_init() and debug_object_activate() allow |
576 | * allocation only if the descriptor callback confirms that the |
577 | * object is static and considered initialized. For non-static |
578 | * objects the allocation needs to be done from the fixup callback. |
579 | */ |
580 | if (unlikely(alloc_ifstatic)) { |
581 | if (!descr->is_static_object || !descr->is_static_object(addr)) |
582 | return ERR_PTR(error: -ENOENT); |
583 | /* Statically allocated objects are considered initialized */ |
584 | state = ODEBUG_STATE_INIT; |
585 | } |
586 | |
587 | obj = alloc_object(addr, b, descr); |
588 | if (likely(obj)) { |
589 | obj->state = state; |
590 | debug_object_is_on_stack(addr, onstack); |
591 | return obj; |
592 | } |
593 | |
594 | /* Out of memory. Do the cleanup outside of the locked region */ |
595 | debug_objects_enabled = 0; |
596 | return NULL; |
597 | } |
598 | |
599 | static void debug_objects_fill_pool(void) |
600 | { |
601 | /* |
602 | * On RT enabled kernels the pool refill must happen in preemptible |
603 | * context -- for !RT kernels we rely on the fact that spinlock_t and |
604 | * raw_spinlock_t are basically the same type and this lock-type |
605 | * inversion works just fine. |
606 | */ |
607 | if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) { |
608 | /* |
609 | * Annotate away the spinlock_t inside raw_spinlock_t warning |
610 | * by temporarily raising the wait-type to WAIT_SLEEP, matching |
611 | * the preemptible() condition above. |
612 | */ |
613 | static DEFINE_WAIT_OVERRIDE_MAP(fill_pool_map, LD_WAIT_SLEEP); |
614 | lock_map_acquire_try(&fill_pool_map); |
615 | fill_pool(); |
616 | lock_map_release(&fill_pool_map); |
617 | } |
618 | } |
619 | |
620 | static void |
621 | __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack) |
622 | { |
623 | enum debug_obj_state state; |
624 | struct debug_bucket *db; |
625 | struct debug_obj *obj; |
626 | unsigned long flags; |
627 | |
628 | debug_objects_fill_pool(); |
629 | |
630 | db = get_bucket(addr: (unsigned long) addr); |
631 | |
632 | raw_spin_lock_irqsave(&db->lock, flags); |
633 | |
634 | obj = lookup_object_or_alloc(addr, b: db, descr, onstack, alloc_ifstatic: false); |
635 | if (unlikely(!obj)) { |
636 | raw_spin_unlock_irqrestore(&db->lock, flags); |
637 | debug_objects_oom(); |
638 | return; |
639 | } |
640 | |
641 | switch (obj->state) { |
642 | case ODEBUG_STATE_NONE: |
643 | case ODEBUG_STATE_INIT: |
644 | case ODEBUG_STATE_INACTIVE: |
645 | obj->state = ODEBUG_STATE_INIT; |
646 | break; |
647 | |
648 | case ODEBUG_STATE_ACTIVE: |
649 | state = obj->state; |
650 | raw_spin_unlock_irqrestore(&db->lock, flags); |
651 | debug_print_object(obj, msg: "init" ); |
652 | debug_object_fixup(fixup: descr->fixup_init, addr, state); |
653 | return; |
654 | |
655 | case ODEBUG_STATE_DESTROYED: |
656 | raw_spin_unlock_irqrestore(&db->lock, flags); |
657 | debug_print_object(obj, msg: "init" ); |
658 | return; |
659 | default: |
660 | break; |
661 | } |
662 | |
663 | raw_spin_unlock_irqrestore(&db->lock, flags); |
664 | } |
665 | |
666 | /** |
667 | * debug_object_init - debug checks when an object is initialized |
668 | * @addr: address of the object |
669 | * @descr: pointer to an object specific debug description structure |
670 | */ |
671 | void debug_object_init(void *addr, const struct debug_obj_descr *descr) |
672 | { |
673 | if (!debug_objects_enabled) |
674 | return; |
675 | |
676 | __debug_object_init(addr, descr, onstack: 0); |
677 | } |
678 | EXPORT_SYMBOL_GPL(debug_object_init); |
679 | |
680 | /** |
681 | * debug_object_init_on_stack - debug checks when an object on stack is |
682 | * initialized |
683 | * @addr: address of the object |
684 | * @descr: pointer to an object specific debug description structure |
685 | */ |
686 | void debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr) |
687 | { |
688 | if (!debug_objects_enabled) |
689 | return; |
690 | |
691 | __debug_object_init(addr, descr, onstack: 1); |
692 | } |
693 | EXPORT_SYMBOL_GPL(debug_object_init_on_stack); |
694 | |
695 | /** |
696 | * debug_object_activate - debug checks when an object is activated |
697 | * @addr: address of the object |
698 | * @descr: pointer to an object specific debug description structure |
699 | * Returns 0 for success, -EINVAL for check failed. |
700 | */ |
701 | int debug_object_activate(void *addr, const struct debug_obj_descr *descr) |
702 | { |
703 | struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; |
704 | enum debug_obj_state state; |
705 | struct debug_bucket *db; |
706 | struct debug_obj *obj; |
707 | unsigned long flags; |
708 | int ret; |
709 | |
710 | if (!debug_objects_enabled) |
711 | return 0; |
712 | |
713 | debug_objects_fill_pool(); |
714 | |
715 | db = get_bucket(addr: (unsigned long) addr); |
716 | |
717 | raw_spin_lock_irqsave(&db->lock, flags); |
718 | |
719 | obj = lookup_object_or_alloc(addr, b: db, descr, onstack: false, alloc_ifstatic: true); |
720 | if (likely(!IS_ERR_OR_NULL(obj))) { |
721 | bool print_object = false; |
722 | |
723 | switch (obj->state) { |
724 | case ODEBUG_STATE_INIT: |
725 | case ODEBUG_STATE_INACTIVE: |
726 | obj->state = ODEBUG_STATE_ACTIVE; |
727 | ret = 0; |
728 | break; |
729 | |
730 | case ODEBUG_STATE_ACTIVE: |
731 | state = obj->state; |
732 | raw_spin_unlock_irqrestore(&db->lock, flags); |
733 | debug_print_object(obj, msg: "activate" ); |
734 | ret = debug_object_fixup(fixup: descr->fixup_activate, addr, state); |
735 | return ret ? 0 : -EINVAL; |
736 | |
737 | case ODEBUG_STATE_DESTROYED: |
738 | print_object = true; |
739 | ret = -EINVAL; |
740 | break; |
741 | default: |
742 | ret = 0; |
743 | break; |
744 | } |
745 | raw_spin_unlock_irqrestore(&db->lock, flags); |
746 | if (print_object) |
747 | debug_print_object(obj, msg: "activate" ); |
748 | return ret; |
749 | } |
750 | |
751 | raw_spin_unlock_irqrestore(&db->lock, flags); |
752 | |
753 | /* If NULL the allocation has hit OOM */ |
754 | if (!obj) { |
755 | debug_objects_oom(); |
756 | return 0; |
757 | } |
758 | |
759 | /* Object is neither static nor tracked. It's not initialized */ |
760 | debug_print_object(obj: &o, msg: "activate" ); |
761 | ret = debug_object_fixup(fixup: descr->fixup_activate, addr, state: ODEBUG_STATE_NOTAVAILABLE); |
762 | return ret ? 0 : -EINVAL; |
763 | } |
764 | EXPORT_SYMBOL_GPL(debug_object_activate); |
765 | |
766 | /** |
767 | * debug_object_deactivate - debug checks when an object is deactivated |
768 | * @addr: address of the object |
769 | * @descr: pointer to an object specific debug description structure |
770 | */ |
771 | void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr) |
772 | { |
773 | struct debug_bucket *db; |
774 | struct debug_obj *obj; |
775 | unsigned long flags; |
776 | bool print_object = false; |
777 | |
778 | if (!debug_objects_enabled) |
779 | return; |
780 | |
781 | db = get_bucket(addr: (unsigned long) addr); |
782 | |
783 | raw_spin_lock_irqsave(&db->lock, flags); |
784 | |
785 | obj = lookup_object(addr, b: db); |
786 | if (obj) { |
787 | switch (obj->state) { |
788 | case ODEBUG_STATE_INIT: |
789 | case ODEBUG_STATE_INACTIVE: |
790 | case ODEBUG_STATE_ACTIVE: |
791 | if (!obj->astate) |
792 | obj->state = ODEBUG_STATE_INACTIVE; |
793 | else |
794 | print_object = true; |
795 | break; |
796 | |
797 | case ODEBUG_STATE_DESTROYED: |
798 | print_object = true; |
799 | break; |
800 | default: |
801 | break; |
802 | } |
803 | } |
804 | |
805 | raw_spin_unlock_irqrestore(&db->lock, flags); |
806 | if (!obj) { |
807 | struct debug_obj o = { .object = addr, |
808 | .state = ODEBUG_STATE_NOTAVAILABLE, |
809 | .descr = descr }; |
810 | |
811 | debug_print_object(obj: &o, msg: "deactivate" ); |
812 | } else if (print_object) { |
813 | debug_print_object(obj, msg: "deactivate" ); |
814 | } |
815 | } |
816 | EXPORT_SYMBOL_GPL(debug_object_deactivate); |
817 | |
818 | /** |
819 | * debug_object_destroy - debug checks when an object is destroyed |
820 | * @addr: address of the object |
821 | * @descr: pointer to an object specific debug description structure |
822 | */ |
823 | void debug_object_destroy(void *addr, const struct debug_obj_descr *descr) |
824 | { |
825 | enum debug_obj_state state; |
826 | struct debug_bucket *db; |
827 | struct debug_obj *obj; |
828 | unsigned long flags; |
829 | bool print_object = false; |
830 | |
831 | if (!debug_objects_enabled) |
832 | return; |
833 | |
834 | db = get_bucket(addr: (unsigned long) addr); |
835 | |
836 | raw_spin_lock_irqsave(&db->lock, flags); |
837 | |
838 | obj = lookup_object(addr, b: db); |
839 | if (!obj) |
840 | goto out_unlock; |
841 | |
842 | switch (obj->state) { |
843 | case ODEBUG_STATE_NONE: |
844 | case ODEBUG_STATE_INIT: |
845 | case ODEBUG_STATE_INACTIVE: |
846 | obj->state = ODEBUG_STATE_DESTROYED; |
847 | break; |
848 | case ODEBUG_STATE_ACTIVE: |
849 | state = obj->state; |
850 | raw_spin_unlock_irqrestore(&db->lock, flags); |
851 | debug_print_object(obj, msg: "destroy" ); |
852 | debug_object_fixup(fixup: descr->fixup_destroy, addr, state); |
853 | return; |
854 | |
855 | case ODEBUG_STATE_DESTROYED: |
856 | print_object = true; |
857 | break; |
858 | default: |
859 | break; |
860 | } |
861 | out_unlock: |
862 | raw_spin_unlock_irqrestore(&db->lock, flags); |
863 | if (print_object) |
864 | debug_print_object(obj, msg: "destroy" ); |
865 | } |
866 | EXPORT_SYMBOL_GPL(debug_object_destroy); |
867 | |
868 | /** |
869 | * debug_object_free - debug checks when an object is freed |
870 | * @addr: address of the object |
871 | * @descr: pointer to an object specific debug description structure |
872 | */ |
873 | void debug_object_free(void *addr, const struct debug_obj_descr *descr) |
874 | { |
875 | enum debug_obj_state state; |
876 | struct debug_bucket *db; |
877 | struct debug_obj *obj; |
878 | unsigned long flags; |
879 | |
880 | if (!debug_objects_enabled) |
881 | return; |
882 | |
883 | db = get_bucket(addr: (unsigned long) addr); |
884 | |
885 | raw_spin_lock_irqsave(&db->lock, flags); |
886 | |
887 | obj = lookup_object(addr, b: db); |
888 | if (!obj) |
889 | goto out_unlock; |
890 | |
891 | switch (obj->state) { |
892 | case ODEBUG_STATE_ACTIVE: |
893 | state = obj->state; |
894 | raw_spin_unlock_irqrestore(&db->lock, flags); |
895 | debug_print_object(obj, msg: "free" ); |
896 | debug_object_fixup(fixup: descr->fixup_free, addr, state); |
897 | return; |
898 | default: |
899 | hlist_del(n: &obj->node); |
900 | raw_spin_unlock_irqrestore(&db->lock, flags); |
901 | free_object(obj); |
902 | return; |
903 | } |
904 | out_unlock: |
905 | raw_spin_unlock_irqrestore(&db->lock, flags); |
906 | } |
907 | EXPORT_SYMBOL_GPL(debug_object_free); |
908 | |
909 | /** |
910 | * debug_object_assert_init - debug checks when object should be init-ed |
911 | * @addr: address of the object |
912 | * @descr: pointer to an object specific debug description structure |
913 | */ |
914 | void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr) |
915 | { |
916 | struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; |
917 | struct debug_bucket *db; |
918 | struct debug_obj *obj; |
919 | unsigned long flags; |
920 | |
921 | if (!debug_objects_enabled) |
922 | return; |
923 | |
924 | debug_objects_fill_pool(); |
925 | |
926 | db = get_bucket(addr: (unsigned long) addr); |
927 | |
928 | raw_spin_lock_irqsave(&db->lock, flags); |
929 | obj = lookup_object_or_alloc(addr, b: db, descr, onstack: false, alloc_ifstatic: true); |
930 | raw_spin_unlock_irqrestore(&db->lock, flags); |
931 | if (likely(!IS_ERR_OR_NULL(obj))) |
932 | return; |
933 | |
934 | /* If NULL the allocation has hit OOM */ |
935 | if (!obj) { |
936 | debug_objects_oom(); |
937 | return; |
938 | } |
939 | |
940 | /* Object is neither tracked nor static. It's not initialized. */ |
941 | debug_print_object(obj: &o, msg: "assert_init" ); |
942 | debug_object_fixup(fixup: descr->fixup_assert_init, addr, state: ODEBUG_STATE_NOTAVAILABLE); |
943 | } |
944 | EXPORT_SYMBOL_GPL(debug_object_assert_init); |
945 | |
946 | /** |
947 | * debug_object_active_state - debug checks object usage state machine |
948 | * @addr: address of the object |
949 | * @descr: pointer to an object specific debug description structure |
950 | * @expect: expected state |
951 | * @next: state to move to if expected state is found |
952 | */ |
953 | void |
954 | debug_object_active_state(void *addr, const struct debug_obj_descr *descr, |
955 | unsigned int expect, unsigned int next) |
956 | { |
957 | struct debug_bucket *db; |
958 | struct debug_obj *obj; |
959 | unsigned long flags; |
960 | bool print_object = false; |
961 | |
962 | if (!debug_objects_enabled) |
963 | return; |
964 | |
965 | db = get_bucket(addr: (unsigned long) addr); |
966 | |
967 | raw_spin_lock_irqsave(&db->lock, flags); |
968 | |
969 | obj = lookup_object(addr, b: db); |
970 | if (obj) { |
971 | switch (obj->state) { |
972 | case ODEBUG_STATE_ACTIVE: |
973 | if (obj->astate == expect) |
974 | obj->astate = next; |
975 | else |
976 | print_object = true; |
977 | break; |
978 | |
979 | default: |
980 | print_object = true; |
981 | break; |
982 | } |
983 | } |
984 | |
985 | raw_spin_unlock_irqrestore(&db->lock, flags); |
986 | if (!obj) { |
987 | struct debug_obj o = { .object = addr, |
988 | .state = ODEBUG_STATE_NOTAVAILABLE, |
989 | .descr = descr }; |
990 | |
991 | debug_print_object(obj: &o, msg: "active_state" ); |
992 | } else if (print_object) { |
993 | debug_print_object(obj, msg: "active_state" ); |
994 | } |
995 | } |
996 | EXPORT_SYMBOL_GPL(debug_object_active_state); |
997 | |
998 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
999 | static void __debug_check_no_obj_freed(const void *address, unsigned long size) |
1000 | { |
1001 | unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; |
1002 | const struct debug_obj_descr *descr; |
1003 | enum debug_obj_state state; |
1004 | struct debug_bucket *db; |
1005 | struct hlist_node *tmp; |
1006 | struct debug_obj *obj; |
1007 | int cnt, objs_checked = 0; |
1008 | |
1009 | saddr = (unsigned long) address; |
1010 | eaddr = saddr + size; |
1011 | paddr = saddr & ODEBUG_CHUNK_MASK; |
1012 | chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1)); |
1013 | chunks >>= ODEBUG_CHUNK_SHIFT; |
1014 | |
1015 | for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) { |
1016 | db = get_bucket(addr: paddr); |
1017 | |
1018 | repeat: |
1019 | cnt = 0; |
1020 | raw_spin_lock_irqsave(&db->lock, flags); |
1021 | hlist_for_each_entry_safe(obj, tmp, &db->list, node) { |
1022 | cnt++; |
1023 | oaddr = (unsigned long) obj->object; |
1024 | if (oaddr < saddr || oaddr >= eaddr) |
1025 | continue; |
1026 | |
1027 | switch (obj->state) { |
1028 | case ODEBUG_STATE_ACTIVE: |
1029 | descr = obj->descr; |
1030 | state = obj->state; |
1031 | raw_spin_unlock_irqrestore(&db->lock, flags); |
1032 | debug_print_object(obj, msg: "free" ); |
1033 | debug_object_fixup(fixup: descr->fixup_free, |
1034 | addr: (void *) oaddr, state); |
1035 | goto repeat; |
1036 | default: |
1037 | hlist_del(n: &obj->node); |
1038 | __free_object(obj); |
1039 | break; |
1040 | } |
1041 | } |
1042 | raw_spin_unlock_irqrestore(&db->lock, flags); |
1043 | |
1044 | if (cnt > debug_objects_maxchain) |
1045 | debug_objects_maxchain = cnt; |
1046 | |
1047 | objs_checked += cnt; |
1048 | } |
1049 | |
1050 | if (objs_checked > debug_objects_maxchecked) |
1051 | debug_objects_maxchecked = objs_checked; |
1052 | |
1053 | /* Schedule work to actually kmem_cache_free() objects */ |
1054 | if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) { |
1055 | WRITE_ONCE(obj_freeing, true); |
1056 | schedule_delayed_work(dwork: &debug_obj_work, ODEBUG_FREE_WORK_DELAY); |
1057 | } |
1058 | } |
1059 | |
1060 | void debug_check_no_obj_freed(const void *address, unsigned long size) |
1061 | { |
1062 | if (debug_objects_enabled) |
1063 | __debug_check_no_obj_freed(address, size); |
1064 | } |
1065 | #endif |
1066 | |
1067 | #ifdef CONFIG_DEBUG_FS |
1068 | |
1069 | static int debug_stats_show(struct seq_file *m, void *v) |
1070 | { |
1071 | int cpu, obj_percpu_free = 0; |
1072 | |
1073 | for_each_possible_cpu(cpu) |
1074 | obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu); |
1075 | |
1076 | seq_printf(m, fmt: "max_chain :%d\n" , debug_objects_maxchain); |
1077 | seq_printf(m, fmt: "max_checked :%d\n" , debug_objects_maxchecked); |
1078 | seq_printf(m, fmt: "warnings :%d\n" , debug_objects_warnings); |
1079 | seq_printf(m, fmt: "fixups :%d\n" , debug_objects_fixups); |
1080 | seq_printf(m, fmt: "pool_free :%d\n" , READ_ONCE(obj_pool_free) + obj_percpu_free); |
1081 | seq_printf(m, fmt: "pool_pcp_free :%d\n" , obj_percpu_free); |
1082 | seq_printf(m, fmt: "pool_min_free :%d\n" , obj_pool_min_free); |
1083 | seq_printf(m, fmt: "pool_used :%d\n" , obj_pool_used - obj_percpu_free); |
1084 | seq_printf(m, fmt: "pool_max_used :%d\n" , obj_pool_max_used); |
1085 | seq_printf(m, fmt: "on_free_list :%d\n" , READ_ONCE(obj_nr_tofree)); |
1086 | seq_printf(m, fmt: "objs_allocated:%d\n" , debug_objects_allocated); |
1087 | seq_printf(m, fmt: "objs_freed :%d\n" , debug_objects_freed); |
1088 | return 0; |
1089 | } |
1090 | DEFINE_SHOW_ATTRIBUTE(debug_stats); |
1091 | |
1092 | static int __init debug_objects_init_debugfs(void) |
1093 | { |
1094 | struct dentry *dbgdir; |
1095 | |
1096 | if (!debug_objects_enabled) |
1097 | return 0; |
1098 | |
1099 | dbgdir = debugfs_create_dir(name: "debug_objects" , NULL); |
1100 | |
1101 | debugfs_create_file(name: "stats" , mode: 0444, parent: dbgdir, NULL, fops: &debug_stats_fops); |
1102 | |
1103 | return 0; |
1104 | } |
1105 | __initcall(debug_objects_init_debugfs); |
1106 | |
1107 | #else |
1108 | static inline void debug_objects_init_debugfs(void) { } |
1109 | #endif |
1110 | |
1111 | #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST |
1112 | |
1113 | /* Random data structure for the self test */ |
1114 | struct self_test { |
1115 | unsigned long dummy1[6]; |
1116 | int static_init; |
1117 | unsigned long dummy2[3]; |
1118 | }; |
1119 | |
1120 | static __initconst const struct debug_obj_descr descr_type_test; |
1121 | |
1122 | static bool __init is_static_object(void *addr) |
1123 | { |
1124 | struct self_test *obj = addr; |
1125 | |
1126 | return obj->static_init; |
1127 | } |
1128 | |
1129 | /* |
1130 | * fixup_init is called when: |
1131 | * - an active object is initialized |
1132 | */ |
1133 | static bool __init fixup_init(void *addr, enum debug_obj_state state) |
1134 | { |
1135 | struct self_test *obj = addr; |
1136 | |
1137 | switch (state) { |
1138 | case ODEBUG_STATE_ACTIVE: |
1139 | debug_object_deactivate(obj, &descr_type_test); |
1140 | debug_object_init(obj, &descr_type_test); |
1141 | return true; |
1142 | default: |
1143 | return false; |
1144 | } |
1145 | } |
1146 | |
1147 | /* |
1148 | * fixup_activate is called when: |
1149 | * - an active object is activated |
1150 | * - an unknown non-static object is activated |
1151 | */ |
1152 | static bool __init fixup_activate(void *addr, enum debug_obj_state state) |
1153 | { |
1154 | struct self_test *obj = addr; |
1155 | |
1156 | switch (state) { |
1157 | case ODEBUG_STATE_NOTAVAILABLE: |
1158 | return true; |
1159 | case ODEBUG_STATE_ACTIVE: |
1160 | debug_object_deactivate(obj, &descr_type_test); |
1161 | debug_object_activate(obj, &descr_type_test); |
1162 | return true; |
1163 | |
1164 | default: |
1165 | return false; |
1166 | } |
1167 | } |
1168 | |
1169 | /* |
1170 | * fixup_destroy is called when: |
1171 | * - an active object is destroyed |
1172 | */ |
1173 | static bool __init fixup_destroy(void *addr, enum debug_obj_state state) |
1174 | { |
1175 | struct self_test *obj = addr; |
1176 | |
1177 | switch (state) { |
1178 | case ODEBUG_STATE_ACTIVE: |
1179 | debug_object_deactivate(obj, &descr_type_test); |
1180 | debug_object_destroy(obj, &descr_type_test); |
1181 | return true; |
1182 | default: |
1183 | return false; |
1184 | } |
1185 | } |
1186 | |
1187 | /* |
1188 | * fixup_free is called when: |
1189 | * - an active object is freed |
1190 | */ |
1191 | static bool __init fixup_free(void *addr, enum debug_obj_state state) |
1192 | { |
1193 | struct self_test *obj = addr; |
1194 | |
1195 | switch (state) { |
1196 | case ODEBUG_STATE_ACTIVE: |
1197 | debug_object_deactivate(obj, &descr_type_test); |
1198 | debug_object_free(obj, &descr_type_test); |
1199 | return true; |
1200 | default: |
1201 | return false; |
1202 | } |
1203 | } |
1204 | |
1205 | static int __init |
1206 | check_results(void *addr, enum debug_obj_state state, int fixups, int warnings) |
1207 | { |
1208 | struct debug_bucket *db; |
1209 | struct debug_obj *obj; |
1210 | unsigned long flags; |
1211 | int res = -EINVAL; |
1212 | |
1213 | db = get_bucket(addr: (unsigned long) addr); |
1214 | |
1215 | raw_spin_lock_irqsave(&db->lock, flags); |
1216 | |
1217 | obj = lookup_object(addr, b: db); |
1218 | if (!obj && state != ODEBUG_STATE_NONE) { |
1219 | WARN(1, KERN_ERR "ODEBUG: selftest object not found\n" ); |
1220 | goto out; |
1221 | } |
1222 | if (obj && obj->state != state) { |
1223 | WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n" , |
1224 | obj->state, state); |
1225 | goto out; |
1226 | } |
1227 | if (fixups != debug_objects_fixups) { |
1228 | WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n" , |
1229 | fixups, debug_objects_fixups); |
1230 | goto out; |
1231 | } |
1232 | if (warnings != debug_objects_warnings) { |
1233 | WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n" , |
1234 | warnings, debug_objects_warnings); |
1235 | goto out; |
1236 | } |
1237 | res = 0; |
1238 | out: |
1239 | raw_spin_unlock_irqrestore(&db->lock, flags); |
1240 | if (res) |
1241 | debug_objects_enabled = 0; |
1242 | return res; |
1243 | } |
1244 | |
1245 | static __initconst const struct debug_obj_descr descr_type_test = { |
1246 | .name = "selftest" , |
1247 | .is_static_object = is_static_object, |
1248 | .fixup_init = fixup_init, |
1249 | .fixup_activate = fixup_activate, |
1250 | .fixup_destroy = fixup_destroy, |
1251 | .fixup_free = fixup_free, |
1252 | }; |
1253 | |
1254 | static __initdata struct self_test obj = { .static_init = 0 }; |
1255 | |
1256 | static void __init debug_objects_selftest(void) |
1257 | { |
1258 | int fixups, oldfixups, warnings, oldwarnings; |
1259 | unsigned long flags; |
1260 | |
1261 | local_irq_save(flags); |
1262 | |
1263 | fixups = oldfixups = debug_objects_fixups; |
1264 | warnings = oldwarnings = debug_objects_warnings; |
1265 | descr_test = &descr_type_test; |
1266 | |
1267 | debug_object_init(&obj, &descr_type_test); |
1268 | if (check_results(addr: &obj, state: ODEBUG_STATE_INIT, fixups, warnings)) |
1269 | goto out; |
1270 | debug_object_activate(&obj, &descr_type_test); |
1271 | if (check_results(addr: &obj, state: ODEBUG_STATE_ACTIVE, fixups, warnings)) |
1272 | goto out; |
1273 | debug_object_activate(&obj, &descr_type_test); |
1274 | if (check_results(addr: &obj, state: ODEBUG_STATE_ACTIVE, fixups: ++fixups, warnings: ++warnings)) |
1275 | goto out; |
1276 | debug_object_deactivate(&obj, &descr_type_test); |
1277 | if (check_results(addr: &obj, state: ODEBUG_STATE_INACTIVE, fixups, warnings)) |
1278 | goto out; |
1279 | debug_object_destroy(&obj, &descr_type_test); |
1280 | if (check_results(addr: &obj, state: ODEBUG_STATE_DESTROYED, fixups, warnings)) |
1281 | goto out; |
1282 | debug_object_init(&obj, &descr_type_test); |
1283 | if (check_results(addr: &obj, state: ODEBUG_STATE_DESTROYED, fixups, warnings: ++warnings)) |
1284 | goto out; |
1285 | debug_object_activate(&obj, &descr_type_test); |
1286 | if (check_results(addr: &obj, state: ODEBUG_STATE_DESTROYED, fixups, warnings: ++warnings)) |
1287 | goto out; |
1288 | debug_object_deactivate(&obj, &descr_type_test); |
1289 | if (check_results(addr: &obj, state: ODEBUG_STATE_DESTROYED, fixups, warnings: ++warnings)) |
1290 | goto out; |
1291 | debug_object_free(&obj, &descr_type_test); |
1292 | if (check_results(addr: &obj, state: ODEBUG_STATE_NONE, fixups, warnings)) |
1293 | goto out; |
1294 | |
1295 | obj.static_init = 1; |
1296 | debug_object_activate(&obj, &descr_type_test); |
1297 | if (check_results(addr: &obj, state: ODEBUG_STATE_ACTIVE, fixups, warnings)) |
1298 | goto out; |
1299 | debug_object_init(&obj, &descr_type_test); |
1300 | if (check_results(addr: &obj, state: ODEBUG_STATE_INIT, fixups: ++fixups, warnings: ++warnings)) |
1301 | goto out; |
1302 | debug_object_free(&obj, &descr_type_test); |
1303 | if (check_results(addr: &obj, state: ODEBUG_STATE_NONE, fixups, warnings)) |
1304 | goto out; |
1305 | |
1306 | #ifdef CONFIG_DEBUG_OBJECTS_FREE |
1307 | debug_object_init(&obj, &descr_type_test); |
1308 | if (check_results(addr: &obj, state: ODEBUG_STATE_INIT, fixups, warnings)) |
1309 | goto out; |
1310 | debug_object_activate(&obj, &descr_type_test); |
1311 | if (check_results(addr: &obj, state: ODEBUG_STATE_ACTIVE, fixups, warnings)) |
1312 | goto out; |
1313 | __debug_check_no_obj_freed(address: &obj, size: sizeof(obj)); |
1314 | if (check_results(addr: &obj, state: ODEBUG_STATE_NONE, fixups: ++fixups, warnings: ++warnings)) |
1315 | goto out; |
1316 | #endif |
1317 | pr_info("selftest passed\n" ); |
1318 | |
1319 | out: |
1320 | debug_objects_fixups = oldfixups; |
1321 | debug_objects_warnings = oldwarnings; |
1322 | descr_test = NULL; |
1323 | |
1324 | local_irq_restore(flags); |
1325 | } |
1326 | #else |
1327 | static inline void debug_objects_selftest(void) { } |
1328 | #endif |
1329 | |
1330 | /* |
1331 | * Called during early boot to initialize the hash buckets and link |
1332 | * the static object pool objects into the poll list. After this call |
1333 | * the object tracker is fully operational. |
1334 | */ |
1335 | void __init debug_objects_early_init(void) |
1336 | { |
1337 | int i; |
1338 | |
1339 | for (i = 0; i < ODEBUG_HASH_SIZE; i++) |
1340 | raw_spin_lock_init(&obj_hash[i].lock); |
1341 | |
1342 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) |
1343 | hlist_add_head(n: &obj_static_pool[i].node, h: &obj_pool); |
1344 | } |
1345 | |
1346 | /* |
1347 | * Convert the statically allocated objects to dynamic ones: |
1348 | */ |
1349 | static int __init debug_objects_replace_static_objects(void) |
1350 | { |
1351 | struct debug_bucket *db = obj_hash; |
1352 | struct hlist_node *tmp; |
1353 | struct debug_obj *obj, *new; |
1354 | HLIST_HEAD(objects); |
1355 | int i, cnt = 0; |
1356 | |
1357 | for (i = 0; i < ODEBUG_POOL_SIZE; i++) { |
1358 | obj = kmem_cache_zalloc(k: obj_cache, GFP_KERNEL); |
1359 | if (!obj) |
1360 | goto free; |
1361 | hlist_add_head(n: &obj->node, h: &objects); |
1362 | } |
1363 | |
1364 | debug_objects_allocated += i; |
1365 | |
1366 | /* |
1367 | * debug_objects_mem_init() is now called early that only one CPU is up |
1368 | * and interrupts have been disabled, so it is safe to replace the |
1369 | * active object references. |
1370 | */ |
1371 | |
1372 | /* Remove the statically allocated objects from the pool */ |
1373 | hlist_for_each_entry_safe(obj, tmp, &obj_pool, node) |
1374 | hlist_del(n: &obj->node); |
1375 | /* Move the allocated objects to the pool */ |
1376 | hlist_move_list(old: &objects, new: &obj_pool); |
1377 | |
1378 | /* Replace the active object references */ |
1379 | for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) { |
1380 | hlist_move_list(old: &db->list, new: &objects); |
1381 | |
1382 | hlist_for_each_entry(obj, &objects, node) { |
1383 | new = hlist_entry(obj_pool.first, typeof(*obj), node); |
1384 | hlist_del(n: &new->node); |
1385 | /* copy object data */ |
1386 | *new = *obj; |
1387 | hlist_add_head(n: &new->node, h: &db->list); |
1388 | cnt++; |
1389 | } |
1390 | } |
1391 | |
1392 | pr_debug("%d of %d active objects replaced\n" , |
1393 | cnt, obj_pool_used); |
1394 | return 0; |
1395 | free: |
1396 | hlist_for_each_entry_safe(obj, tmp, &objects, node) { |
1397 | hlist_del(n: &obj->node); |
1398 | kmem_cache_free(s: obj_cache, objp: obj); |
1399 | } |
1400 | return -ENOMEM; |
1401 | } |
1402 | |
1403 | /* |
1404 | * Called after the kmem_caches are functional to setup a dedicated |
1405 | * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag |
1406 | * prevents that the debug code is called on kmem_cache_free() for the |
1407 | * debug tracker objects to avoid recursive calls. |
1408 | */ |
1409 | void __init debug_objects_mem_init(void) |
1410 | { |
1411 | int cpu, ; |
1412 | |
1413 | if (!debug_objects_enabled) |
1414 | return; |
1415 | |
1416 | /* |
1417 | * Initialize the percpu object pools |
1418 | * |
1419 | * Initialization is not strictly necessary, but was done for |
1420 | * completeness. |
1421 | */ |
1422 | for_each_possible_cpu(cpu) |
1423 | INIT_HLIST_HEAD(&per_cpu(percpu_obj_pool.free_objs, cpu)); |
1424 | |
1425 | obj_cache = kmem_cache_create(name: "debug_objects_cache" , |
1426 | size: sizeof (struct debug_obj), align: 0, |
1427 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE, |
1428 | NULL); |
1429 | |
1430 | if (!obj_cache || debug_objects_replace_static_objects()) { |
1431 | debug_objects_enabled = 0; |
1432 | kmem_cache_destroy(s: obj_cache); |
1433 | pr_warn("out of memory.\n" ); |
1434 | return; |
1435 | } else |
1436 | debug_objects_selftest(); |
1437 | |
1438 | #ifdef CONFIG_HOTPLUG_CPU |
1439 | cpuhp_setup_state_nocalls(state: CPUHP_DEBUG_OBJ_DEAD, name: "object:offline" , NULL, |
1440 | teardown: object_cpu_offline); |
1441 | #endif |
1442 | |
1443 | /* |
1444 | * Increase the thresholds for allocating and freeing objects |
1445 | * according to the number of possible CPUs available in the system. |
1446 | */ |
1447 | extras = num_possible_cpus() * ODEBUG_BATCH_SIZE; |
1448 | debug_objects_pool_size += extras; |
1449 | debug_objects_pool_min_level += extras; |
1450 | } |
1451 | |